Re: [PATCH] Support empty ranges with bounds information

On 03/02/21 14:20, Joel Jacobson wrote:
> This would effectively mean there would be absolutely no semantic changes at all.
>
> I will work on a new patch to try out this idea.

I may have been assuming a degree of orthogonality in SQL that isn't
really there ... only in a few situations (like creating an index) do
you easily get to specify a non-default operator class to use when
comparing or hashing a value.

So perhaps a solution could be built on the same range machinery, but
requiring some new syntax in CREATE TYPE ... AS RANGE, something like
WITH POSITIONS. A new concrete range type created that way would not
be a whole different kind of a thing, and would share most machinery
with other range types, but would have the position-remembering
behavior. Given a range type created over int4 in that way, maybe
named int4prange, the regexp_positions function could return one of those.

Regards,
-Chap